Dementia cases could triple globally by 2050
Friday January 7th 2022
The number of adults living with dementia is expected to nearly triple by 2050, according to a new global report, published today.
The Global Burden of Disease study, the first to provide forecasting estimates for 204 countries worldwide, estimates cases will increase from approximately 57 million in 2019 to 153 million in 2050.
The study, which is published in the latest edition of *The Lancet Public Health*, estimates that dementia cases will rise in every country, with the smallest increases in high-income Asia Pacific (53%) and western Europe (74%), and the largest growth in north Africa and the Middle East (367%) and eastern sub-Saharan Africa (357%).
The authors, the GBD 2019 Dementia Forecasting Collaborators, project particularly large increases in Qatar (1926%), the United Arab Emirates (1795%), and Bahrain (1084%).
However, they say improved access to education could lead to six million fewer cases of dementia worldwide by 2050.
The study examined four risk factors for dementia - smoking, obesity, high blood sugar, and low education - to highlight the impact they will have on future trends.
For example, improvements in global education access are expected to reduce dementia prevalence by 6·2 million cases worldwide by 2050, but this will be countered by growth in obesity, high blood sugar, and smoking, which are anticipated to result in an additional 6·8 million dementia cases.
Lead author Emma Nichols, of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, USA, said: “Our study offers improved forecasts for dementia on a global scale as well as the country-level, giving policy makers and public health experts new insights to understand the drivers of these increases, based on the best available data.
“These estimates can be used by national governments to make sure resources and support are available for individuals, caregivers, and health systems globally.
“At the same time, we need to focus more on prevention and control of risk factors before they result in dementia. Even modest advances in preventing dementia or delaying its progression would pay remarkable dividends.
“To have the greatest impact, we need to reduce exposure to the leading risk factors in each country. For most, this means scaling up locally appropriate, low-cost programmes that support healthier diets, more exercise, quitting smoking, and better access to education. And it also means continuing to invest in research to identify effective treatments to stop, slow, or prevent dementia.”
Dementia is the seventh leading cause of death worldwide and one of the major causes of disability and dependency among older people globally.
Although dementia mainly affects older people, it is not an inevitable consequence of ageing, with a Lancet Commission published in 2020 suggesting that up to 40% of dementia cases could be prevented or delayed if exposure to 12 known risk factors - low education, high blood pressure, hearing impairment, smoking, midlife obesity, depression, physical inactivity, diabetes, social isolation, excessive alcohol consumption, head injury, and air pollution - sere eliminated.
Globally, more women are affected by dementia than men and this pattern is expected to remain in 2050.
Co-author Dr Jaimie Steinmetz from IHME, University of Washington, said: “It’s not just because women tend to live longer. There is evidence of sex differences in the biological mechanisms that underlie dementia. It’s been suggested that Alzheimer’s disease may spread differently in the brains of women than in men, and several genetic risk factors seem related to the disease risk by sex.”
The authors acknowledge that their analysis was limited by a lack of high-quality data in several parts of the world and by studies using different methodologies and definitions of dementia.
They also say they were unable to consider all 12 risk factors from the 2020 Lancet Commission report because they were limited to risk factors included in the GBD study and only included risk factors with strong evidence of association.
The study examined the overall prevalence of dementia, and the authors say clinical subtypes, such as vascular dementia, may have different relationships with risk factors, which could affect the results.
Nichols E, Steinmetz JD, Vollset SE et al. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. *The Lancet Public Health*. January 2022. DOI: 10.1016/S2468-2667(21)00249-8
Tags: Africa | Asia | Brain & Neurology | Elderly Health | Europe | Mental Health | World Health
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